Mostly freshwater perennial herbs rooted in the substrate with creeping, budding rhizomes. Leaves spirally arranged, blades linear or expanded when floating, with parallel venation and a basal sheath and ligule. Flower clusters in spikes held above the water. Flowers regular, bisexual, 4-parted, small. Perianth segments fleshy. Stamens 4, opposite and joined to the perianth segments. Ovary superior. Carpels 4, alternating with the stamens. Fruit a head of nutlets or drupelets, usually floating.

Grown in ponds and sometimes in aquaria.

2 genera and about 90-100 species, cosmopolitan. Australia has 2 genera and about 10 species.

Leaves floating and submerged; flowers bisexual, 4-parted; ovules 1 per carpel.

Source: Spencer, R. (2005). Potamogetonaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.